Plasma processing method and plasma processing apparatus

Abstract

A method for processing a substrate includes: supplying a pulsed source RF signal to an antenna disposed above a chamber, the pulsed source RF signal including a plurality of source cycles each having a source operating state and a source non-operating state after the source operating period; and supplying a pulsed bias RF signal to a lower electrode disposed in a substrate support provided in the chamber, the pulsed bias RF signal including a plurality of bias cycles having a same pulse frequency as that of the plurality of source cycles, each bias cycle having a bias operating state during a bias operating period and a bias non-operating state during a bias non-operating period after the bias operating period. A transition timing to the bias operating state in each bias cycle is delayed with respect to a transition timing to the source operating state in a corresponding source cycle.

What is claimed is: 
     
         1 . A method for processing a substrate comprising:
 providing a plasma processing apparatus including a chamber, a substrate support disposed in the chamber, a lower electrode disposed in the substrate support, and an antenna disposed above the chamber;   supplying a pulsed source RF signal to the antenna, the pulsed source RF signal including a plurality of source cycles, each source cycle having a source operating state during a source operating period and a source non-operating state during a source non-operating period after the source operating period; and   supplying a pulsed bias RF signal to the lower electrode, the pulsed bias RF signal including a plurality of bias cycles having a same pulse frequency as that of the plurality of source cycles, each bias cycle having a bias operating state during a bias operating period and a bias non-operating state during a bias non-operating period after the bias operating period,   wherein a transition timing to the bias operating state in each bias cycle is delayed with respect to a transition timing to the source operating state in a corresponding source cycle,   the source non-operating period overlaps with the bias non-operating period, and   the bias operating period in each bias cycle overlaps with the source operating period in a next source cycle.   
     
     
         2 . The method according to  claim 1 , wherein the source operating state has at least two source power levels, and
 the bias operating state has at least two bias power levels.   
     
     
         3 . The method according to  claim 2 , wherein the source operating state has a first source power level and a second source power level after the first source power level, the bias operating state has a first bias power level and a second bias power level after the first bias power level, and
 the pulsed bias RF signal transitions to the bias operating state during the source non-operating period in each source cycle.   
     
     
         4 . The method according to  claim 3 , wherein the pulsed bias RF signal transitions from the first bias power level to the second bias power level during the source non-operating period in each source cycle. 
     
     
         5 . The method according to  claim 4 , wherein a transition from the first source power level to the second source power level in each source cycle is substantially synchronized with a transition from the bias operating state to the bias non-operating state in each bias cycle. 
     
     
         6 . The method according to  claim 5 , wherein the first source power level is greater than the second source power level. 
     
     
         7 . The method according to  claim 5 , wherein the first source power level is less than the second source power level. 
     
     
         8 . The method according to  claim 7 , wherein the second bias power level is greater than the first bias power level. 
     
     
         9 . The method according to  claim 7 , wherein the second bias power level is less than the first bias power level. 
     
     
         10 . The method according to  claim 3 , wherein a transition from the first source power level to the second source power level in each source cycle is substantially synchronized with a transition from the bias operating state to the bias non-operating state in each bias cycle. 
     
     
         11 . The method according to  claim 3 , wherein the first source power level is greater than the second source power level. 
     
     
         12 . The method according to  claim 3 , wherein the first source power level is less than the second source power level. 
     
     
         13 . The method according to  claim 3 , wherein the second bias power level is greater than the first bias power level. 
     
     
         14 . The method according to  claim 3 , wherein the second bias power level is less than the first bias power level. 
     
     
         15 . A method for processing a substrate comprising:
 providing a plasma processing apparatus including a chamber, a substrate support disposed in the chamber, a lower electrode disposed in the substrate support, and an upper electrode disposed above the substrate support;   supplying a pulsed source RF signal to the upper electrode or the lower electrode, the pulsed source RF signal including a plurality of source cycles, each source cycle having a source operating state during a source operating period and a source non-operating state during a source non-operating period after the source operating period; and   supplying a pulsed bias RF signal to the lower electrode, the pulsed bias RF signal including a plurality of bias cycles having a same pulse frequency as that of the plurality of source cycles, each bias cycle having a bias operating state during a bias operating period and a bias non-operating state during a bias non-operating period after the bias operating period,   wherein a transition timing to the bias operating state in each bias cycle is delayed with respect to a transition timing to the source operating state in a corresponding source cycle,   the source non-operating period overlaps with the bias non-operating period, and   the bias operating period in each bias cycle overlaps with the source operating period in a next source cycle.   
     
     
         16 . The method according to  claim 15 , wherein the source operating state has at least two source power levels, and
 the bias operating state has at least two bias power levels.   
     
     
         17 . The method according to  claim 16 , wherein the source operating state has a first source power level and a second source power level after the first source power level,
 the bias operating state has a first bias power level and a second bias power level after the first bias power level, and   the pulsed bias RF signal transitions to the bias operating state during the source non-operating period in each source cycle.   
     
     
         18 . The method according to  claim 17 , wherein the pulsed bias RF signal transitions from the first bias power level to the second bias power level during the source non-operating period in each source cycle. 
     
     
         19 . The method according to  claim 18 , wherein a transition from the first source power level to the second source power level in each source cycle is substantially synchronized with a transition from the bias operating state to the bias non-operating state in each bias cycle. 
     
     
         20 . The method according to  claim 17 , wherein a transition from the first source power level to the second source power level in each source cycle is substantially synchronized with a transition from the bias operating state to the bias non-operating state in each bias cycle.